Quantcast
Environmental News for a Healthier Planet and Life

Help Support EcoWatch

Eastern Monarch Butterflies at Risk of Extinction

Animals
Eastern Monarch Butterflies at Risk of Extinction

By U.S. Geological Survey

Long-term declines in the overwintering Eastern population of North American monarch butterflies are significantly increasing their likelihood of becoming extinct over the next two decades, according to Scripps Institution of Oceanography at UC San Diego and U.S. Geological Survey (USGS) research published today.

Monarch Male Butterfly—A monarch butterfly (Danaus plexippus) resting and sunning at an overwintering site in the Piedra Herrada Monarch Butterfly Sanctuary in Mexico. This individual is a male, identifiable by the black spot on each hindwing. Photo credit: Steve Hilburger / USGS

The new study, available in the journal Scientific Reports, found that the Eastern migratory monarch population declined by 84 percent from the winter of 1996-1997 to the winter of 2014-2015. Using this information, the study demonstrated that there is a substantial chance—11 to 57 percent—of quasi-extinction over the next 20 years. A quasi-extinct population is one with so few remaining individuals left that recovery is impossible. While the remaining individuals may survive for a short time, the population as a whole will inevitably go extinct.

Monarch Butterflies on Tree—A group of monarch butterflies (Danaus plexippus) covers an oyamel fir tree (Abies religiosa) at an overwintering site in the Piedra Herrada Monarch Butterfly Sanctuary in Mexico. Photo credit: Steve Hilburger / USGS

“Because monarch numbers vary dramatically from year to year depending on weather and other factors, increasing the average population size is the single-most important way to provide these iconic butterflies with a much-needed buffer against extinction," Brice Semmens, the lead author of the study and a scientist at Scripps, said.

Semmens said that as an example of this variability, just after the analysis concluded, the World Wildlife Fund Mexico and partners reported a large increase in monarch numbers since last year. However, this increase was followed by a recent winter storm that may have adversely affected the population. The authors emphasized that although one good winter—as occurred this year—is positive news, higher average monarch numbers are necessary for reducing the long-term risk of quasi-extinction.

Because counting individual monarchs is challenging, scientists measure population size based on the geographic area that their colonies cover while spending the winter in Mexico. The U.S., Mexico and Canada aim to increase the number of Eastern monarchs wintering in Mexico so that they occupy about six hectares or about 15 acres, by 2020. This year's population size increased substantially to about four hectares or close to 10 acres. The population was 1.13 hectares (about 2.8 acres) during the winter of 2014-2015 and at its lowest, 0.67 hectares (about 1.7 acres) during the 2013-2014 winter.

The Scripps and USGS) scientists found that if the Eastern population reaches the six-hectare goal announced in last year's national pollinator strategy, the quasi-extinction risk over 20 years would decrease by more than half.

“Previously published research suggested that the most effective way to increase monarch numbers is to focus on the restoration of their breeding habitat," said USGS scientist Darius Semmens, a coauthor of the report. “Over the previous two winters, Eastern monarch populations were very low, indicating a higher risk of losing the species. If their numbers continue to grow, as they did this year, the risk will decrease."

Scripps and the USGS collaborated with scientists from the University of Arizona, Iowa State University, University of Minnesota and the University of Kansas on the study. The research was conducted as part of the Monarch Conservation Science Partnership, a team of scientists and resource managers working together to help inform the management of monarch butterflies. The partnership was hosted by the USGS Powell Center for Analysis and Synthesis in Fort Collins, Colorado.

YOU MIGHT ALSO LIKE

Shocking Footage of Illegal Fishing in the Indian Ocean

Great Bear Landmark Agreement Protects World's Largest Temperate Rainforest

First New Butterfly Species Found in Alaska in 28 Years: Is it an Ancient Hybrid?

Love Wildlife? Check Out These 11 Stunning Photos From Yellowstone National Park

In an ad released by Republican Voters Against Trump, former coronavirus task force member Olivia Troye roasted the president for his response. Republican Voters Against Trump / YouTube

Yet another former Trump administration staffer has come out with an endorsement for former Vice President Joe Biden, this time in response to President Donald Trump's handling of the coronavirus pandemic.

Read More Show Less

EcoWatch Daily Newsletter

Climate Group

Every September for the past 11 years, non-profit the Climate Group has hosted Climate Week NYC, a chance for business, government, activist and community leaders to come together and discuss solutions to the climate crisis.

Read More Show Less

Trending

A field of sunflowers near the Mehrum coal-fired power station, wind turbines and high-voltage lines in the Peine district of Germany on Aug. 3, 2020. Julian Stratenschulte / picture alliance via Getty Images

By Elliot Douglas

The coronavirus pandemic has altered economic priorities for governments around the world. But as wildfires tear up the west coast of the United States and Europe reels after one of its hottest summers on record, tackling climate change remains at the forefront of economic policy.

Read More Show Less
Monarch butterflies in Mexico's Oyamel forest in Michoacan, Mexico after migrating from Canada. Luis Acosta / AFP / Getty Images

By D. André Green II

One of nature's epic events is underway: Monarch butterflies' fall migration. Departing from all across the United States and Canada, the butterflies travel up to 2,500 miles to cluster at the same locations in Mexico or along the Pacific Coast where their great-grandparents spent the previous winter.

Read More Show Less
The 30th First Annual Ig Nobel Prize Ceremony on Sept. 17 introduced ten new Ig Nobel Prize winners, each intended to make people "laugh then think." Improbable Research / YouTube

The annual Ig Nobel prizes were awarded Thursday by the science humor magazine Annals of Improbable Research for scientific experiments that seem somewhat absurd, but are also thought-provoking. This was the 30th year the awards have been presented, but the first time they were not presented at Harvard University. Instead, they were delivered in a 75-minute pre-recorded ceremony.

Read More Show Less

Support Ecowatch